Container filling

ABSTRACT

Aerosol containers of the internal piston type have gas under pressure introduced thereinto at one side of the piston through the bottom wall of the container. This is done by advancing a gassing head into sealing engagement with the container bottom while automatically opening a passage through the head and the container bottom for discharge of the gas under pressure into the container and then sequentially automatically closing the passage at the bottom wall of the container. The container bottom wall may contain either a normally open valving structure that is automatically closed by a cam actuated impact mechanism after filling, or a normally closed valve that is opened when the gassing head moves against the container bottom wall and automatically closed by gas pressure within the container.

United States Patent McGeary [151 3,654,743 '[451 Apr. 11, 1972 [54] CONTAINER FILLING [72] Inventor: George Jerome McGeary, Bronx, NY.

[73] Assignee: Colgate-Palmolive Company, New York,

abandoned. which is a continuation ofSer. No. 627.334.

Mar. 31. 1967, abandoned.

[52] US. Cl ..53/88, 53/268, 141/20,

141/1 13, 141/147 [51] Int. Cl. ..B65b 7/16, B65b 31/02 [58] Field of Search ..53/7, 36, 43, 47, 79, 88, 99,

1,058,094 4/1913 Phelps ..14l/113 X 2,989,993 6/1961 Osmond et a1... 141/20 3,176,727 4/1965 Rousseau ..l4l/20 3,179,309 4/1965 Cope ..222/389 FOREIGN PATENTS OR APPLICATIONS 1,293,786 4/1962 France ..53/36 Primary Examiner-Edward J. Earls Attorney-Strauch, Nolan, Neale, Nies & Kurz ABSTRACT Aerosol containers of the internal piston type have gas under pressure introduced thereinto at one side of the piston through the bottom wall of the container. This is done by advancing a gassing head into sealing engagement with the container bottom while automatically opening a passage through the head and the container bottom for discharge of the gas under pressure into the container and then sequentially automatically closing the passage at the bottom wall of the container. The

222/389 container bottom wall may contain either a normally open valving structure that is automatically closed by a cam actu- [56] References Clted ated impact mechanism after filling, or a normally closed UNITED STATES PATENTS valve that is opened when the gassing head moves against the container bottom wall and automatically closed by gas pres- 2,189,852 2/1940 Ye cski ..53/79 sure within the container 3,124,917 3/1964 Dobbins..... ...l4l/l13 UX 3,237,659 3/1966 Albrecht ,.14l/20 7 Claims, 9 Drawing Figures 1 l l l I l l l PATENTEDAPR 1 1 I972 3,654,743

SHEEI 1 OF 3 INVENTOR. George Jerome Ma Geary ATTOR N EYS PATENTEmPR 1 1 m2 3,654,743

sumzur's DISENGAGE 75 SEAL 8 FILL INVENTOR. George Jerome Mc Geo/y ATTORNEYS w R m PATENTEDAPR 1 1 I972 SHEET 3 [IF 3 INVENTOR George Jerome Me 6 ea ry M%e/%M7 W ATTORNEYS CONTAINER FILLING RELATED APPLICATIONS This application is a continuation of copending application, Ser. No. 861,224, filed Sept. 17, 1969, which is a continuation of application, Ser. No. 627,334, filed Mar. 31, 1967 for Container Filling, both now abandoned.

CONTAINER FILLING This invention relates to a system for introducing propellant gas into so-called aerosol type dispenser containers of the internal piston type, wherein the gas is admitted through a valving arrangement in the bottom of the container.

Most of the aerosol container gas filling machines in general use introduce propellant gas through the container discharge head, as disclosed for example in U. S. Letters Patent No. 3,013,591. The containers filled in such machines usually have imperforate bottom walls. With the advent of internal piston type aerosol containers came requirements for introducing gas into the container space at the lower side of the piston, and it has been proposed to introduce the propellant gas through a valve opening in the bottom wall of the otherwise complete container structure. The present invention is particularly concerned with a new and useful system and automatic apparatus for the efficient bottom filling of such containers with propellant gas, and this is its principal object.

It is a further object of the invention to provide a novel system and apparatus for introducing propellant gas through the bottom wall of an aerosol type container wherein a valving structure in said bottom wall is open during admission of the gas and is automatically closed, either by internal gas pressure of the container or by positive action, after the gas filling operation.

Another object of the invention is to provide a machine for the automatic gassing of aerosol type containers wherein a gas filling head of novel construction is brought into sealed gas introducing relation with the valved bottom wall of the container and separated therefrom after the filling operation is complete. Pursuant to this object the gas filling head may comprise a passage defining structure connected with a source of gas under pressure and containing a control valve, and the passage is sealed with the bottom of the container before the control valve is opened; and further objects of the invention provide novel structures and combinations of elements for automatic operation in this sequence.

Further objects of the invention will appear as the description proceeds in connection with the appended claims and the annexed drawings wherein:

FIG. 1 is fragmentary view partially diagrammatic and in section for illustrating a system and apparatus for the automatic gas filling of internal piston container of the aerosol type according to a preferred embodiment of the invention;

FIG. 1A is a fragmentary view mainly in section showing the relative positions of the parts before a container is placed on the tray;

FIGS. 2 and 3 are enlarged fragmentary views partly broken away and in section showing the internal structure of a gassing head in two of its operational conditions;

FIG. 4 is a diagrammatic view illustrating the operation sequence of the FIG. 1-3 system;

FIG. 5 is an enlarged fragmentary view partly in section and partly diagrammatic showing the invention in another embodiment for gas filling the type of container shown in FIGS. 68;

FIG. 6 is an elevation partially broken away and in section showing a container having a different type of valved opening from that of FIGS. 1-3; and

FIGS. 7 and 8 are sectional and top plan views respectively of the filling valve used in the container of FIG. 6.

An aerosol type container 11 is shown in FIG. 1 and it comprises a cylindrical can body 12 the upper end of which is closed by a sealed top wall 13 mounting the usual dispensing valve having an upwardly projecting hollow discharge stem 14 which may be depressed to open the dispensing valve. Usually the can body is made of stiff metal or plastic.

A piston 15 is freely slidably mounted within the can body and acts as a pressure responsive barrier separating the container interior into a product space 16 above the piston and in communication with the dispensing valve and a propellant gas space 17 below the piston. Piston 15 is preferably a thinwalled integral element formed from a flexible resilient material capable of conforming to the container walls such as from relatively stiff sheet polyethylene, and its depending cylindrical skirt 18 has its smooth outer periphery in close sliding engagement with the smooth cylindrical internal surface 19 of the can body.

Space 16 is adapted to be filled with a fluent product to be dispensed, and space 17 is adapted to contain propellant gas under a superatmospheric pressure which is isolated from space 16 by the piston. The gas pressure in space 17 tends to expand the piston skirt into sealing relation with the can wall. In operation the consumer depresses valve stem 14 to open the space 16 to atmosphere, and the piston 15 is displaced upwardly due to the pressure differential to discharge the product from space 16.

In practicing the invention the container, with piston 15 installed inside and having the dome-shaped bottom wall 21 rigidly secured thereon as by the crimped rim 22, is filled through the open upper end with the product to be dispensed, and then the top wall 13 mounting the usual dispensing valve is sealingly attached as by the crimped rim at 23. Wall 21 is domed inwardly for pressure resistance. The central part of wall 21 is formed with an opening 24, which contains either the valving structure 25 of FIGS. 2 and 3 or that of FIGS. 6-8 as will appear.

Referring to FIG. 1, an upper turntable 26 and a series of circumferentially spaced can trays 27 are rotated together about a common vertical axis at a constant continuous speed. Each container to be filled is axially held between the tray 27 and an upper holder 28 on the turntable which is suitably recessed at 30 to engage the container without depressing the valve stem. Each tray 27 is vertically aligned with a holder 28 on the turntable, there being a series of trays uniformly spaced around the axis of rotation.

A series of containers 11 are fed in single file onto the circumferentially successive trays 27 at a feeding station so that a container is disposed over each tray opening 29. As soon as a container is disposed on its tray 27, the tray 27 is displaced vertically upwardly to axially clamp the container between the tray 27 and holder 28 so that the tray, container and turntable rotate together through most of a revolution of the turntable. At the end of a revolution the tray drops down to release filled container 11 which is then removed from the tray. The foregoing may be accomplished in any suitable conventional manner known in the art.

Below-each opening 29, the tray 27 mounts a filling head assembly 31 comprising a yoke 32 rigidly supporting a vertical axis cylinder 33 that projects through opening 29. Each yoke 32 is suspended from tray 27 as by at least two pairs of telescoping tubes 34 and 35 having a pin and slot slide connection at 36, 37 and housing a compression spring 38. Each tray 27 is secured as by a set screw 41 to a vertically reciprocable post 42 that mounts on its lower end a follower roller 43 engaging a stationary cam track 44. When a container is moved onto a tray 27, the roller 43 is engaged with a low section of cam track 44, and then as the tray moves in its circular path roller 43 moves up a ramp in the track to a higher track level 45 shown in FIG. 1 wherein the container 11 is clamped between the tray and the turntable.

Spaced posts 46 project down from yoke 32 and carry rollers 47 engaging a stationary dual cam track 48, and when rollers 47 encounter a sloping upward change in level of track 48 this shifts cylinder 33 vertically upwardly as will be explained.

Cylinder 33 (FIG. 2) is internally formed with a cylindrical bore 51 and the upper end of the bore terminates in a reduced diameter wall opening 52 and an outwardly flared top recess 53. Surrounding recess 53 is an annular groove 54 mounting a resilient seal ring 55 such as a rubber O-ring. The function of ring 55 is to sealingly engage the bottom container wall when cylinder 33 is raised to the FIG. 2 position during operation.

Internally of cylinder 33 a valve element 56 is slidably mounted in bore 51. Element 56 is formed with an annular recessed section 57 that is disposed opposite a side wall port 58 in the cylinder mounting the end of a flexible gas pressure supply conduit 59. Conduit 59 is connected to the gas pressure source by a suitable manifold (not shown) that permits flow between the stationary source and the moving conduit. Above section 57, element 56 is formed with a plurality of longitudinal flutes 61, and its upper end reduces to a small diameter section 62 slidable within opening 52. Above section 62 an axially projecting solid button 60 is formed on element 56. The small diameter section 62 is likewise longitudinally fluted at 63. The reduced neck of element 56 is formed with an annular groove 64 mounting a resilient seal ring 65 of synthetic rubber which under certain conditions of operation is adapted to sealingly engage the annular face 66 of bore 51 just below opening 52 as will appear.

A stem 67 projects downwardly from element 56 in alignment with the stem 68 on a slidable piston 69 in the lower end of bore 51. Stems 67 and 68 are surrounded by a compression spring 71 that tends to urge piston 69 and element '56 apart. Piston 69 carries a peripheral seal ring 72 to prevent escape of gas from bore 51.

The lower end of cylinder 33 carries a threaded cap 73 through which slidably projects a piston rod 74 carrying a roller 75 engaged with a third stationary cam track 76. A change in level of track 76 varies the vertical position of piston 69 as will appear.

FIG. 1A shows the relative disposition of cylinder 33 and tray 27 which exists at the time that the container 27 is placed on the tray and prior to the time that the cylinder 33 is raised to the container engaging and sealing position of FIG. 2. At this time the cylinder 33 is in its lowermost position indicated also at 33 in FIG. 1, with piston 69 bottomed in bore 51 and with spring 71 expanded to urge valve element 56 into gas tight sealing engagement with bore 51 so that seal ring 65 is compressed against face 66 and no gas escapes through opening 52. Since the upper end of cylinder 33 is below the level of the top surface of tray 27, it does not interfere with sliding of container 11 onto the tray.

Operation will now be described after a container 11 is placed on the tray 27 and the tray has been displaced upwardly to clamp a container 11 in the FIG. 1 position. It will be appreciated that container 11 at this time already contains the product in space 16, top wall 13 is sealed in place and piston is at its lowest level as determined by skirt 18 resting on the can bottom wall. In the illustration of the invention shown in FIGS. l-3, the can bottom wall opening 24 contains an admission valve structure in the form of a plug 77 of some plastically deformable material such as lead, solder, plastic or the like formed with an angular through passage 78.

FIGS. 1 and 2 also show the condition wherein yoke 32 and cylinder 33 have been displaced upwardly by rollers 47 encountering an upwardly sloping ramp of track 48. Cylinder 33 is projected upwardly through tray opening 29 until seal ring 55 compressively engages and seals gas tight with the bottom wall 21 of the clamped container 11.

At the same time button 60 engages plug 77 and the valve element 56 is displaced downwardly against the force of spring 71 sufficiently to separate ring 65 from seat 66 (FIG. 2) and thereby open the passage through cylinder 33 to gas flow from conduit 59 to the space between the container and the cylinder. This downward displacement of valve 56 results in collapse of spring 71 and solid abutment of valve stem 67 against stem 68 of the piston 69. The axial spacing of these stems 67 and 68 must be such as to permit passage opening by the time the stems abut.

With seal ring 65 out of contact with face 66, there is a through passage for gas under pressure to flow from conduit 59 through space 57, flutes 61, the upper part of bore 51, flutes 63 and the space confined by the seal ring 55 into passage 78 to pressurize the container space 17. This takes only a relatively short period, the parts being in the position shown in FIG. 2. Any necessary downward displacement of element 56 is permitted by spring 71 seated on piston 69 which at the time is held stationary by the track 76, and the force needed to overcome the spring is not enough to close passage 78.

After space 17 is pressurized, roller 75 on the piston rod encounters a ramp leading sharply upwardly to a higher track level 79 as shown in FIG. 3, yoke 32 being retained at the same level as during filling, and this results in piston 69 being quickly upwardly displaced to act through solidly engaged stems 67 and 68 to immediately and quickly displace element 56 upwardly to impart a relatively sharp blow to plug 77 with sufficient force to deform plug 77 to permanently close the valve structure passage 78 and thus seal off the bottom of container 11 against escape of gas under pressure from space 17. Upward displacement of element 56 also moves the seal ring 65 into compressive sealing contact with seat 66 to arrest further discharge of propellant gas from bore 51. This condition is shown in FIG. 3. The material of plug 77 is such that it retains the deformed condition imparted to it by the striking force of button 60.

Container 11 is now charged and sealed. Rollers 47 and 75 now encounter downwardly sloping cam track sections, so that tray 27 descends to separate container 11 from holder 28 and cylinder 33 descends back into tray opening 29 to the FIG. 1A position. As cylinder 33 descends roller 75 also encounters a downwardly sloping part of track 76 so that piston 69 drops back toward the FIG. 2 position, but during this time spring 71 expands to keep valve element 56 in its upper sealing position of FIG. 3 to maintain bore 51 sealed against gas leakage.

When the tray containing the filled sealed container 11 reaches a further point in its rotation, the container is removed therefrom and the tray passes on to repeat the foregoing cycle. This action takes place at each tray rotating with the turntable.

FIG. 4 diagrammatically illustrates the cam track arrangement for carrying out the foregoing wherein closing impact at plug 77 is timed to take place at the end of the gas filling operation and prior to breaking of the seal between the gas filling head and the container.

FIG. 5 illustrates another filling head arrangement for gas filling containers of the type shown in FIGS. 6-8. Container 11 is the same as that of FIG. 1 but the valve structure at opening 24 in the bottom wall is different.

In FIGS. 6-8, valving structure 81 comprises a cup shaped sheet metal member 82 having an annular external groove 83 that sealingly fits peripherally in container wall opening 24. The lower end of member 82 contains an upwardly open annular channel 84 surrounding a circular central opening 85 disposed at slightly higher level. An integral valve element 86 comprises a plastic or like lightweight flexible disc having an outer diameter about the same as the inner diameter of member 82 to which it is peripherally secured at 90.

Disc 86 is formed with a central spherical seating projection 87 fitting snugly over opening 85 in closed valve position of FIG. 7 and a circular series of through ports 88 that are formed through the relatively thin annular web 89 that connects seat 87 and the disc periphery and are disposed in a row above channel 84. When disc 86 is seated downwardly as by gas pressure in space 17 with seat 87 on opening 85, the bottom of container 11 is sealed closed as in the earlier embodiment. Disc 86 is similarly formed top and bottom so that no special care need be taken in assembly.

In FIG. 5 the filling head 91 is rigid with yoke 32 which is mounted to be elevated and lowered by a similar cam track arrangement to FIGS. l3.

Filling head 91 contains an upright cylindrical bore 92 within which is slidable a valve element 93 that is similar to valve element 56 except for its upper portion as will be described. Valve element 93 is formed with an annular recessed portion 94 that is disposed opposite the side wall port connected to gas supply conduit 59. Above recessed portion 94 element 93 is slidably engaged with the bore wall and formed with longitudinal surface flutes 95 communicating portion 94 with the bore above the valve element. The upper end of valve element 93 reduces to a cylindrical section 96 slidable in reduced bore 97 at the top of head 91. The reduced end of the valve element also mounts a resilient O-ring 98 that is adapted to seat on annular surface 99 under the force of spring 101 in the lower end of the bore when valve element 93 is in closed position.

The upper end of valve element 93 carries a rigid button 102 that, as shown in FIG. 5, is adapted to engage disc 86 and flex it upwardly to unseat projection 87 from opening 85 when the head 91 is raised to the FIG. 5 position. An internal valve passage 103 is provided between openings 104 near the top of button 102 and openings 105 located upwardly of seal ring 98.

In operation the container 11 is placed on tray 27 over opening 29 in the same manner as in FIG. 1, at which time the filling head 91 is at its lowermost position with its upper end within opening 29 below the tray surface level. The container is clamped between the turntable as in FIG. 1, and then as the tray rotates rollers 47 encounter an upwardly sloping ramp leading to the high portion of track 48 as shown in FIG. 5. This elevates filling head 91 to sealingly engage the bottom of the container 11 and automatically opens the gas supply passage to permit discharge of gas under pressure through conduit 59, valve element 93 and valve 81 into the container.

As the filling head 91 is displaced upwardly the seal ring 55 compresses tightly in sealed engagement with the bottom of the container. At the same time button 102 engages valve disc 86 whereby the valve element 93 is displaced downwardly within bore 92 until the stems 107 and 106 on the valve element and head respectively abut, and the seal at 98, 99 is separated, spring 101 being compressed, and at the same time projection 87 is unseated from container valve opening 85 to place the interior of the container in fluid communication with bore 92. Thus gas under pressure flows through the passage consisting of annular space 94, flutes 95, the upper end of bore 92, openings 105, passage 103, openings 104, container valve opening 85 and apertures 88 in the valve disc into the space 17 within the container.

After space 17 has been charged, rollers 47 encounter a descending ramp whereby the yoke is lowered to allow valve element 93 to be raised by spring 101 to closed position where ring 98 seats at 99 and to separate the filling head from the container. The superatmospheric propellant gas pressure within the container automatically immediately reseats disc 86 to close valve opening 85 and prevent escape of the gas from the container.

In some forms of this embodiment of the invention the stem 106 may be mounted on a piston in bore 92 like the arrangement of FIG. 2, so that after the valve element 93 has been displaced to collapse the spring 101 the valve element may be lifted a small distance, short of engaging seal ring 98 with seat 99, as by the cam and roller arrangement shown in FIG. 2 to effect more positive unseating of projection 87 from the openin 85.

What is claimed and desired to be secured by Letters Patent 1. Apparatus for introducing a charge of propellant gas through filling valve structure in a transverse bottom wall of a container of the type having a dispensing valve in its upper end and wherein said filling valve structure is distinct from said container wall and secured within an opening in said container wall, comprising support means which comprises a turntable rotatable about a vertical axis and adapted for holding a succession of spaced containers upright, a gas filling head disposed below each container, each head having a passage therethrough and being mounted for vertical movement between a lower position out of contact with the associated container on said support means and an upper position where it engages the bottom wall of the associated container on said support means, each said filling head having an upper surface and a compressible resilient annular sealing means mounted on said upper surface in surrounding relation to the upper end of said passage and adapted to sealingly engage the bottom wall of said associated container in surrounding relation to the filling valve structure thereof when said filling head has been displaced to said upper position, filling head raising and lowering means comprising fixed cam track means cooperating with follower means on said head for effecting said headmovements during predetermined distances of rotation of said support means, and normally closed valve means within each filling head having a movable valve element engageable in abutment with the filling valve structure of the associated container to displace said valve element to valve open position when said filling head is moved to said upper position for connecting the interior of said container through said passage with a source of propellant gas under pressure only when said head is sealingly engaged with said container, said valve means being automaticallyclosed when said filling head is separated from said container.

2. In the apparatus defined in claim 1, each said passage comprising a bore, said valve element being slidable in said bore, means resiliently biasing said valve element to close said bore, and means on said valve element projecting out of said bore beyond the upper surface of said filling head for engaging said filling valve structure of the associated container when the filling head is brought into sealing engagement with the container.

3. In the apparatus defined in claim 1, means for securing each container against movement on said support means, said support means having openings over which each container is mounted, said filling head in said lower position being chiefly below said support means and said filling head in said upper position projecting through a support means opening into sealing engagement with said container.

4. In the apparatus defined in claim 1, said valve structure in each container comprising a deformable plug-initially having a through passage, and means for displacing said valve means on each head upwardly to deform said plug to close said plug passage after introduction of fluid pressure into a container.

5. In the apparatus defined in claim 4, said means for displacing said valve means to deform said plug comprising means actuated in automatic synchronism with said filling head raising and lowering means.

6. In the apparatus defined in claim 1, cooperating vertically separable means on said turntable for fixing each said container thereon during the gas filling operation, and means for cyclically actuating said separable means in timed relation with filling head said raising and lowering means.

7. Apparatus for introducing a charge of propellant gas through valve structure in a bottom wall opening of a container of the type having a dispensing valve in its upper end comprising support means for holding the container upright, a gas filling head having a passage therethrough mounted for movement between a lower position out of contact with the container on said support means and an upper position where it engages the bottom wall of the container on said support means, said support means comprising a turntable driven about a vertical axis, means for cyclically raising and lowering said filling head comprising fixed cam track means cooperating with follower means on said head, said filling head having an upper surface and a compressible resilient annular sealing means mounted on said upper surface in surrounding relation to the upper end of said passage and adapted to sealingly engage the bottom of said container in surrounding relation to said valve structure when said filling head has been displaced to said upper position, and normally closed valve means within said filling head engageable with said valve structure to open said valve means when said filling head is in said upper position for connecting the interior of said container through said passage with a source of propellant gas under pressure only when said head is sealingly engaged with said container, said valve means being automatically closed when said filling head is separated from said container, cooperating vertically separable means on said turntable for fixing said container thereon during the gas filling operation, and means for cyclically separating and bringing toward each other said separable means in timed relation with said filling head raising and lowering means, said separable means comprising a fixed turntable part engaging the top of the container and a vertically slidable displaceable part on said turntable on which the bottom of said container rests, and said displaceable part having an opening through which said filling head moves to sealingly engage the container thereon.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION.

Patent No. 3 I 743 Dated April ll, 1972 I Inventor(s) George Jerome McC-l-eary' It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below;

Column 1, line 50, after "FIG. 1 is" insert --a--.

Column 6, claim 6, line 5, after "with" insert --said same line, after "head" delete --said- Signed and sealedthis 29th day of August 1972 (SEAL) Attest:

EDWARD P I.FLEICHER,JR. I ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents l FORM P0 1050 (10-69) USCOMM-DC 60376-P69 U.. GOVERNMENT PRINTING OFFICE: I909 O-3 $6 334 

1. Apparatus for introducing a charge of propellant gas through filling valve structure in a transverse bottom wall of a container of the type having a dispensing valve in its upper end and wherein said filling valve structure is distinct from said container wall and secured within an opening in said container wall, comprising support means which comprises a turntable rotatable about a vertical axis and adapted for holding a succession of spaced containers upright, a gas filling head disposed below each container, each head having a passage therethrough and being mounted for vertical movement between a lower position out of contact with the associated container on said support means and an upper position where it engages the bottom wall of the associated container on said support means, each said filling head having an upper surface and a compressible resilient annular sealing means mounted on said upper surface in surrounding relation to the upper end of said passage and adapted to sealingly engage the bottom wall of said associated container in surrounding relation to the filling valve structure thereof when said filling head has been displaced to said upper position, filling head raising and lowering means comprising fixed cam track means cooperating with follower means on said head for effecting said head movements during predetermined distances of rotation of said support means, and normally closed valve means within each filling head having a movable valve element engageable in abutment with the filling valve structure of the associated container to displace said valve element to valve open position when said filling head is moved to said upper position for connecting the interior of said container through said passage with a source of propellant gas under pressure only when said head is sealingly engaged with said container, said valve means being automatically closed when said filling head is separated from said container.
 2. In the apparatus defined in claim 1, each said passage comprising a bore, said valve element being slidable in said bore, means resiliently biasing said valve element to close said bore, and means on saiD valve element projecting out of said bore beyond the upper surface of said filling head for engaging said filling valve structure of the associated container when the filling head is brought into sealing engagement with the container.
 3. In the apparatus defined in claim 1, means for securing each container against movement on said support means, said support means having openings over which each container is mounted, said filling head in said lower position being chiefly below said support means and said filling head in said upper position projecting through a support means opening into sealing engagement with said container.
 4. In the apparatus defined in claim 1, said valve structure in each container comprising a deformable plug initially having a through passage, and means for displacing said valve means on each head upwardly to deform said plug to close said plug passage after introduction of fluid pressure into a container.
 5. In the apparatus defined in claim 4, said means for displacing said valve means to deform said plug comprising means actuated in automatic synchronism with said filling head raising and lowering means.
 6. In the apparatus defined in claim 1, cooperating vertically separable means on said turntable for fixing each said container thereon during the gas filling operation, and means for cyclically actuating said separable means in timed relation with filling head said raising and lowering means.
 7. Apparatus for introducing a charge of propellant gas through valve structure in a bottom wall opening of a container of the type having a dispensing valve in its upper end comprising support means for holding the container upright, a gas filling head having a passage therethrough mounted for movement between a lower position out of contact with the container on said support means and an upper position where it engages the bottom wall of the container on said support means, said support means comprising a turntable driven about a vertical axis, means for cyclically raising and lowering said filling head comprising fixed cam track means cooperating with follower means on said head, said filling head having an upper surface and a compressible resilient annular sealing means mounted on said upper surface in surrounding relation to the upper end of said passage and adapted to sealingly engage the bottom of said container in surrounding relation to said valve structure when said filling head has been displaced to said upper position, and normally closed valve means within said filling head engageable with said valve structure to open said valve means when said filling head is in said upper position for connecting the interior of said container through said passage with a source of propellant gas under pressure only when said head is sealingly engaged with said container, said valve means being automatically closed when said filling head is separated from said container, cooperating vertically separable means on said turntable for fixing said container thereon during the gas filling operation, and means for cyclically separating and bringing toward each other said separable means in timed relation with said filling head raising and lowering means, said separable means comprising a fixed turntable part engaging the top of the container and a vertically slidable displaceable part on said turntable on which the bottom of said container rests, and said displaceable part having an opening through which said filling head moves to sealingly engage the container thereon. 